The long-term objective of this research is to better understand how stress affects health and cognition and how the cognitive consequences of stress are related to the health outcomes. The first specific aim is to examine the cognitive benefits of expressive writing and how the cognitive benefits are related to the health benefits of expressive writing. Cognitive and health variables will be measured before and after participants expressively write about ongoing stressful events in their lives. The second aim is examine how expressive writing produces cognitive and health benefits, focusing mainly on the changes in one's autobiographical memory for stressful events. Cognitive and health outcomes variables will be measured before and after participants write about various aspects of their memory (sensory, affective, integration of event, etc.). In addition, cognitive and health benefits will be examined in participants who write about more than one stressful event in their life, to determine if the benefits of expressive writing are additive. The third specific aim is to test the potential benefits of the expressive writing technique with persons with Posttraumatic stress disorder (PTSD). The cognitive and health outcomes of person with PTSD who write about their traumatic experience will be compared with the cognitive and health outcomes from persons without PTSD who write about a stressful life event.